Oil and gas operations involve accessing underground hydrocarbon reservoirs contained within subterranean formations. Such hydrocarbon reservoirs are also accompanied by large amounts of water which can negatively affect oil production. As hydrocarbons are drawn from the well over time, water displaces the hydrocarbons in the formation and therefore becomes an increasing fraction during production. Once the production of water becomes too high, the cost of obtaining the decreasing amounts of hydrocarbon becomes too great and the reservoir is then abandoned. Accordingly, hydrocarbon production and the life of the reservoir are greatly determined by the effectiveness of water management.
The initial production of hydrocarbons from a reservoir is driven largely by the pressure naturally present in the subterranean formation. Accordingly, due to natural fractures or hydraulic fracturing in the formation, hydrocarbons are drawn to the well under the natural pressures in the system. However, once the natural pressures are relieved, other measures must be taken to maintain production. Accordingly a secondary means for driving the production of hydrocarbons in the well includes water flooding operations. Water flooding involves injecting brine, saltwater or some other fluid into the formation to increase pressure and drive the hydrocarbons toward a well for production.
The measure of the effectiveness of water flooding operations is referred to as conformance. In particular, conformance relates to the ability of the flood front of the injected water to uniformly sweep hydrocarbons from all portions of the reservoir as the water propagates through the system. With imperfect conformance, a certain amount of the hydrocarbons will be left within various pockets of the reservoir. Conformance improvement refers to the ability to access such pockets and drive hydrocarbons from hard to reach or less permeable portions of the formation.
Current technologies applied in the oil industry for improved conformance include mechanical solutions such as plugs, packers, and the like. Chemical solutions can also be employed including monomer systems, polymer gels, and relative permeability modifiers (RPM). Such technologies involve placement of materials to block or restrict the flow of water from water zones into productive hydrocarbon zones. Accordingly, additional technologies are required to further improve conformance.